Amazon.com released a statement this afternoon seeking to explain why thousands of books — including many gay- and lesbian-themed titles — were removed from its sales rankings over the weekend.

“This is an embarrassing and ham-fisted cataloging error for a company that prides itself on offering complete selection,” said Drew Herdener, the Seattle company’s communications director.

“It has been misreported that the issue was limited to Gay & Lesbian themed titles — in fact, it impacted 57,310 books in a number of broad categories such as Health, Mind & Body, Reproductive & Sexual Medicine, and Erotica. This problem impacted books not just in the United States but globally. It affected not just sales rank but also had the effect of removing books from Amazon’s main product search.”

Amazon previously blamed a “glitch,” which seemed to intensify anger among some gay and lesbian activists who suspected homophobic censorship.

Books without sales rankings are still listed on Amazon.com but deleted from its best-seller lists, reducing the chances that they’ll come to the attention of someone browsing the Web site for popular titles.

Neil Giuliano, president of the Gay & Lesbian Alliance Against Defamation in New York, released a statement earlier today saying it contacted Amazon and was led to believe the deletions were a mistake.

“We expect to start seeing evidence of its correction immediately, and any loss of visibility of gay-themed books as a result of this error will be made right by Amazon,” Giuliano said. “It is so important that stories about the lives of our community are available, and that companies like Amazon promote these titles in equal fashion.”